1. Field of the Invention
The present invention relates to a laser diode particularly suitable for high output usage and a method of manufacturing the same.
2. Description of the Related Art
In general, in a high output laser diode, it is known that Catastrophic Optical Damage (COD) is easily caused by temperature rise associated with recombination at an end face thereof and increase of light absorption. Such COD disturbs high output operation and high reliability. Thus, in order to prevent the COD from being generated, in the past, various improvements have been made.
For example, examples of such improvements include a method of decreasing the light density in the vicinity of the end face. For example, in Japanese Unexamined Patent Application Publication No. 2002-158402, in a ridge waveguide laser diode, the thickness from an active layer to the surface of a ridge side is larger in the end face and in the vicinity thereof, and smaller in the central portion of the ridge stripe. Thereby, in the vicinity of the end face, the light spot size is magnified and the light density is decreased, and thus the COD level is able to be increased. Further, in the central portion of the ridge stripe, a leak current to the ridge side is able to be decreased, and thus the threshold current is able to be kept low.